1. Those are completely different sets of words, some of which look more similar than others, some of which have languages related to each other (and others don't), and some are explained by other reasons.

2. Randomly picking words that "look similar" is not a good scientific approach. If you want to show any meaningful relationship, then you need a lot of systematic data showing patterns.

These words do not look similar. The only similarity is that they have a consonant-vowel (CV) pattern, which is easily explained because they are frequent words, and therefore likely to develop short forms over time. There is nothing more to explain here.

In the case of ì˜ˆ (ja, yes), this is one of those universal onomatopeic words: in vast numbers of languages, the expression "yes" is some variant of [je]. The Chinese version is, OTOH, from a different source, namely "(it) is", which incidentally is a common source of word for "true". ì•ˆ and IE ne are only minimally similar. The more-universal onomatopeic forms of negation are pa, ma, ka.